1. Field of the Invention
The present invention relates to a method and an apparatus for the batching out of items with non-uniform weights, in particular foodstuff items. The invention is closely linked with the so-called grader technique, involving the use of a portioning-out apparatus having conveyor means for moving a flow of items through a dynamic weighing station and thereafter along a sorting-Out path, along which there is arranged a row of receiver stations with associated diverter means which, controlled from a control unit connected with the weighing station, can be actuated in a selective manner in order to divert the individual items into respective receiver stations for building up therein batches of items amounting to at least a predetermined total minimum weight or target weight, within given limits.
2. Description of Related Art
The prior art, e.g. as disclosed in GB 2 116 732 and WO 96/08322, provides for the repeated building up of one full batch in each of the receiver stations, but in particular in WO 96/08322, it is indicated that it is perfectly possible to operate with different target weights in or for different receiver stations, hereinafter also referred to as xe2x80x9cbins.xe2x80x9d Such a differentiation is useful for different purposes, as discussed in more detail below, but already at this place, it should be emphasized that a major aspect of the present invention is the use of at least some. of the receiver stations as substations for receiving selected items to be merged into one full batch with a predetermined target weight, and thus, holding items received from more than one receiver station.
This will introduce a possibility of co-batching items selected on the basis of criteria other than or in addition to the weight criterion, whether referring to characteristics of she incoming items, e.g. color or xe2x80x9ctypexe2x80x9d, or to acts to be performed on the items upon their delivery to one or another substation, respectively, e.g. in being selectively provided with a color marking or being orientationally reversed or otherwise treated or handled in or at the outlet side of the respective receiver substations, before the collection of the items in the xe2x80x9cfinal batch.xe2x80x9d
A highly relevant example of the use of the invention pertains to the industrial handling and packaging of the cut pieces of parted poultry, with specific reference to the huge chicken industry. In that connection, by way of example, it is a widespread practice to produce so-called xe2x80x9ccatering packages,xe2x80x9d each holding four isolated groups of predetermined numbers of breast pieces, thigh pieces, leg pieces and wings, respectively, said groups having part-weights such that when they are brought together they will amount to a predetermined total weight. A typical example will be to produce packages (boxes),.each with four bags containing 24 pieces, i.e., with a total content of 96 pieces with a total weight of 34 lbs. for the pieces from the lower weight class and 38 lbs. for those from the higher weight class. A suitable part-weight is determined for each of the four bags, thus, for example, for the xe2x80x9clightxe2x80x9d pieces
12.7 lb breast
10.2 lb thigh
6.2 lb wings
4.9 lb lower leg (xe2x80x9cdrumstickxe2x80x9d)
in all
34.0 lb for 96 pieces.
In order to maintain these part-weights in a reasonably reliable manner, in practice it will be unavoidable that some overweight will be involved, and when these overweights are summed up in the composition of the four bags, the result can be a quite considerable overweight (xe2x80x9cgive-awayxe2x80x9d) of each of the total packages. To these costs must be added those of additional labor that may be needed with larger high capacity packing lines.
Using the grader technique for the production of the individual xe2x80x9cbagsxe2x80x9d will greatly facilitate the building up of the required subgroups therein, even with a minimized overweight thereof, yet still with some overweight and still with operators having to merge the different bags into final packages.
According to the present invention, however, it will no longer be important to use the criterion that each of the four xe2x80x9cbagsxe2x80x9d must absolutely appear with an independent minimum weight. With the manually-controlled portioning-out, the criterion has actual significance in that, for the operators, it will be almost hopeless work both to control a more-or-less correct bag filling and to carry out a xe2x80x9cbag groupingxe2x80x9d for fixed weight on the basis of bags whose weight can lie both slightly above and slightly below the specified xe2x80x9ccategory weight,xe2x80x9d but with the use of a suitable grader control this will not be any problem, in principle even completely without manual assistance. The system can be programmed in such a way that in groups of four different receiver bins, the respective item portions are built up for the filling of xe2x80x9cbagsxe2x80x9d with more-or-less the desired own weight, but with the main condition that the weight of the four bag portions together shall be down as closely as possible to the prescribed total weight of the sum of the bags.
In practice, this will mean a drastic change with respect to the overweight occurring in the total portions (xe2x80x9cthe boxesxe2x80x9d), in that this will regularly be able to be reduced to a previously unobtainable minimum, while at the same time the operating work can be limited to an absolute minimum. The available chicken pieces can be utilized with increased efficiency without any noticeable inconvenience for the associated customers. For these it will be quite without significance whether a bag with, e.g., 24 leg pieces weighs slightly less than expected, if this is compensated for by corresponding overweight occurring in some of the other bags. In such cases therefore, the customer is supplied with a fully useable and acceptable quantity.
Moreover, with the invention the work at the producers can be achieved with a minimum of waste in the form of items or xe2x80x9cbagsxe2x80x9d which are not suitable for batching together with other items or bags for the building-up of portions with reasonable relevant weight, and such a minimization, which does not concern the customers, will obviously also be of the greatest interest to the producer.
In order to achieve the desired result, the grader equipment must be kept informed concerning the kind of items successively supplied, i.e., if the variance in the weight of said items is not sufficient in itself to clearly identify the item types. If, for example, a leg piece from a heavy chicken weighs wore than a breast piece from a lighter chicken, the control equipment will not be able to clearly identify the item type, and consequently it may not have the possibility of being able to place the item together with an item of the same kind. This problem can possibly be overcome by using visual scanning equipment which can identify the kind of successively arriving item, or by the equipment feeding the item being supervised by an operator who provides the control equipment with a type-identifying code.
It is also possible to arrange the equipment which feeds the item to the grader in such an operator-controlled way that the item per definition will be introduced in a predetermined type sequence, whereby the control equipment will automatically be informed concerning the kind of item successively being supplied.
A further and highly realistic possibility is for the item to be fed along separate tracks, from which the item are automatically transferred to the weighing line with associated automatic transfer of identification signals to the control computer. Moreover, there is the possibility of being able to use two parallel weighing lines to which two types of item are fed selectively, namely respective pairs of item types, which in general have such great mutual weight difference that each of the two weighing lines can themselves identify the item types. The items can, e.g., hereby be supplied in a coherent, irregular flow to a separating station where two operators transfer the respective item types to each their weighing line, and ensure that the items are placed on these with sufficient space between them so that they can be identified at the subsequent weighing.
On the level of principle, it will be possible to carry out the disclosed method with the use of an ordinary grader, the control unit of which is programmed so as to execute batching of the relevant numbers of items of different types up to a predetermined total target weight, and so as to thereby allocate the items of the different types to respective different receiver stations. Thus, the grader will make use of a relevant number of its ordinary receiver bins for the forming of one batch, the item sub groups or xe2x80x9cbagsxe2x80x9d being manually or automatically unloaded from the bins and brought together into one xe2x80x9cboxxe2x80x9d.
For a grader according to the invention, however at least when the arm is dedicated to operate exclusively with the relevant xe2x80x9cmulti product batchingxe2x80x9d, it is preferred for the sake of simplicity to arrange for the relevant xe2x80x9csub binsxe2x80x9d to be physically grouped close to each other and to be in operative connection with outlet guide means leading to a caution batch collector station. The latter may be a container, a platform at a belt, from which, the received bags can be transferred to a relevant xe2x80x9cboxxe2x80x9d, or the collector station may be the box itself, then the operator takes care to place in each collector wits a box ready for direct reception of a following batch. The bins or xe2x80x9creceiver substationsxe2x80x9d are used for the bagging of the items, and the said outlet guide means may then be constituted by a fixed chute installation leading the bags to a specific collector site for each group of interrelated bins.
The invention is relevant whenever there is a reason to distinguish between items which, weightwise, can be accepted as belonging to one arid the earn batch, whatever the criterion of such distinguishing may be. Specific xe2x80x9ctypesxe2x80x9d of items as discussed above will not be limited to different body parts of poultry, but may as well refer to a selection e.g. of three red apples in batches of ten red and green apples or seven large slices of smoked salmon in batches of twenty larger and smaller slices. Also, if whole fishes are supplied with non-uniform orientation, it may be desirable to effect a turning of some of them once it has been decided to which batch they should be allocated in order to ensure that in that particular batch the fishes will be deposited generally with opposite orientations in order to effectively fill up a fish box to a reasonably horizontal level. It follows that whenever the fishes are supplied with uniform orientation it may or will be required to effect a turning of some of them upon their being allocated to a specific batch, and in this respect it is very convenient if or when such a turning can be effected methodically for all items delivered to one receiver substation, while in a counterpart station the items are received and transferred to the collector box without being turned.
As discussed in more detail in PCT/DK99/00235, these turnings can be established in several different manners, however widely based on the separation principle of the present invention.
Also, in connection with almost all kinds of foodstuff pieces there may be pieces which are of equal weights, but are otherwise different in various respects, be it with respect to color, specific dimensions such as length, structure or partial damaging, and for a given batch it may be desirable to load a box with xe2x80x9cregularxe2x80x9d pieces at one end of the box and xe2x80x9cirregularxe2x80x9d pieces at the other end of the same box. According to the invention, this is easily achievable once the relevant character of the pieces has been detected, e.a., by means of a vision system, viz, in supplying the selected pieces selectively to two different receiver stations, from which they are conveyed to the respective opposed end areas of a collector box, preferably along a common chute element.
In the following the invention will be described in more detail with reference to the drawing.